Safety pilot fob gas heaters



E. R. KoPPEL SAFETY PILOT FOR GAS HEATERS Filed Aug. 14, 1941 ATTORNEY Sept. 4, 1945.

Patented Sept. 1945 UNITED STATES SAFETY PILOT FOR GAS HEATERS Ernst R. Koppel, Wauwatosa, Wis., assignor to A. 0. Smith Corporation,` Milwaukee, Wisl, a corporation of New York Application August 14,

(Cl. 15S-117.1)

. 6- Claims.

This invention relates to a safety pilot for gas heaters, and has been applied to the control of pilots for thermostatically operated heaters in heating water for domestic use.

The principal object of the invention is to provide a safety control for the pilot iiame so that should the pilot become extinguished, both the main gas supply to the burner and that to'the pilotl would be shut oif and there would be no leakage of gas through the pilot burner.

Another object is to provide such a control with an alternative passage with manual control for supplying gas to the pilot burner for starting.

Another object is to provide that the manual control referred to is required to be in a position closing the alternative passage when the pilot is heated and the main safety valve is open.

Other objects and advantages of the .invention will be explained in connection with the description of a number of embodiments illustrated in the accompanying drawing.

ln the drawing:

Figure 1 is a front elevation of the control unit of one embodiment, showing the pilot valve handle in starting position;

Fig. 2 is a side elevation of the unit taken from the right of Fig. 1 showing the manual shut ofi valve closed;

Fig. 3 is a view similar to Fig. l, partly in section, showing the pilot valve .in normal heater operating position and showing the main gas valve open;

Fig. 4 is a, side elevation of Fig. 3, viewed from the right;

Fig. 5 is a vertical section taken on line 5-5 of Fig. 3 showing the main thermostat safety control valve;

Fig. 6 is a front elevation showing a unit, similar to that in Fig. l, in which the lugs on the shut ofi valve are eliminated; y

Fig. 7 is a front elevation partly in section of a modiiled form of unit in Awhich the manual shut off valve and auxiliary pilot starting valve are' disposed to operate together, the valve being shown in pilot lighting position;

Fig. 8 is a view similar lto Fig. '7 of another iorm in whicha sliding pilot valve is employed, showing the valves in pilot lighting position;

Fig. 9 is a section on line 9-9 of Fig. 8; and

Fig. 10 is a section on line .I0-I0 of Fig. 8, showing the pilot valve in normal heater operating position.

In accordance with the invention, a thermostatically controlled valve provides gas from the 1941, serial No. 406,*186

low pressure side of the main shut oil valve to the pilot, and a manually set valve is provided to supply gas for starting the pilot from the high pressure side of the main shut oi.valve.

By low and high pressure sides it is not intended to indicate that the gas ils' at any diilerent pressure on the two sides when the valve is open, but that there is a difference when the valve is closed, and the high pressure side is that of the inlet to the valve while the low pressure side is that of the outlet from the valve.

Referring to the drawing, the unit comprises a cast metal body I providing two main valve chambers, one for the manual shut oif valve 2 and the other for the thermostatically controlled snap shut off valve 3.

A pilot burner 4 is threaded at its inner end into the casing l and a thermostat 5 extending parallel to the burner tube and above it is also threaded into the casing. The central rod 8 of the thermostat is connected to and operates valve 3. The construction of valve 3 and thermostat 5 may be similar to present day standard thermostat valves used on the main burner for water heaters.

The hand shut off valve 2 may also be of standard construction usually `comprising a conical body l, having a passage 8 therethrough disposed to register with an inlet passage 9 and outlet passage It in the body I, when in open position, and to be turned so as to fail to register with the passage 9 when in the closed position. The valve 2 has a handle I I for turning it.

inlet 9, passage B, outlet I0, and through valve 3 to pipe I2 leading to the burner control valve.

Thus, in order to supply gas to the main burner,

both the manualshut off valve 2 and thermostatically controlled shut oil valve 3 must be open. Since the valve 3 is controlled by heat from the pilot name, it shuts oil. the entire gas supplyln case the pilot llame goes out. I

The pilot burner is supplied with gas through passage i3, and a two-way valve I4 is disposed for connecting passage I3 either to passage I6 leading from the low pressure side of valve I, or to passage i6 leading from the gas supply duct 8.

The valve Il comprises a conical member l1 secured for turning in a complementary opening in,body I. The passage I3 connects with 'the inner end oi member Il, the latterhaving an axial hole therethrough. A radial hole I8 through one side of member I1 connects the passage I3 to either the passage I6 or I6. A center The gas forlthe main burner passes throughplug I2 screws into the arial opening in member I1 and serves to adjust the opening of hole l2 to adjust the supply of gas to the pilot name. A cap 22 covers the outer end of member I1 to protect against leakage of gas past the plug I2 and has secured thereto the manual operatinglever' not escape through either'burner while valve 2 is closed.

To light .the burner the operator turns the manual shut off valve 2 to 03" position and turns the pilot valve Il to the right by means of lever 2| until hole l2 registers with passage Il passes through a complementary opening 'in the casing to prevent turning of the body. v

When starting thexburner, the push button 22 is pressed inwardly moving valve body 21 against spring 22. 'I'his eilects the registry of passage 22 with a passage 22 leading from the gas supply passage I' and with a passage 2l leading to the pilot burner I'. Both radial passages 2i and 22 are closed at this time. When the pilot thermostat l' becomes heated valve 2' is opened and the operator can then release button 22. A needle valve 25 controls the gas supply to the pilot burner 4'.

When the burner is on, as shown in Fig. 10. the y radial passage 2i registerswith passage 22 leadi ing from the low pressure side of the main so as to supply gas from inlet -2 through passag`e\ I8, hole I2, member I1 and passage I2 to the pilot burner. He then vlights the pilot.

After the pilot ame becomes hot, thermostat 2 operates to open valve 2 and the operator turns YVvalve 2 to "on" position, and releases lever 2l,

which returns to normaLpositlon by reason of spring 22 and supplies gas to the pilot burner from the low pressure side of' valve 2 through passage I2.

Several different constructions may be employed for holding the lever 2i to the` right against the spring 22 while the pilot is lighted and heats thermostat I.

In the construction of Figures l to 5,.inclu sive. a lug 22 is disposed on the body I to hold vlever 2i down. while the pilot is being lighted. The lever 2I is released from lug 22 either manually or by a cam -22 on handle il when valve 2' is turned to open position.

In'Fig. 6 the lugs 22 and 22 are eliminated and lever 2| is held in starting position solely by' the operator. Upon operation of thermostat i the operator releases lever 2l and it returns to' n mal operating position.

thermostat valve 2', and radial passage 22 registers with passage 22 leading therefrom to the pilot burner 4. The ends of passage 22 are closed by the housing surrounding they valve.

The invention is a substantial improvement`vl` over previous constructions since it provides absolute safety in case the pilot becomes extinguished. At the same time, it allows for sate and easy starting of the burner. l 1

Various embodiments of the invention may be employed within the scope and spirit thereof as set forthin the accompanying claims.

The invention is hereby claimed as follows:

l. In a safety control foi` gas heaters employing a pilot burner and a safety shut oif valve Voperated thermostatically in response to heat therefrom, a manual shut of! valve on the high pressure side of said safety shut oi! valve for supplying gas thereto, means manually operable to supply gas to the pilot for starting the pilot burner when said manual shut off valve is closed,

'and means operable in response to the opening InFig.7amodifledfonnisshown. Inthis.

embodiment the valve 2' in addition to supplying the burner through port 2' serves also as the pilot `valve by providing an auxiliary passage 2l in conical body 1' positioned to connectpassage I2' to the inlet s. The radial location of passage 2l relative to port 2' is suchthat it connects the passages 2' and I6 when the valve handle-ll' is turned about 90 from either onj' or "oir" posif tion. Thus, theport 2' is shut oi! when 22 registers with inlet 2' and the latter is opened through port 2', valve 2' andpassage Il' leading from the low pressure side of valve 2' when valve -`2' is open.- Port 2' -is closed toA both ports 2' and I2' when handle II isturned to oi! position.

In Figures 8. 9 and l0 the pilot'valve is a slide l, valve operated manually by a push button 22.1 'Ihe cylindrical valve body 21 is normally biased outwardly by a spring 22 at its rear end; The body 21 has 'a longitudinal passage 22 extending from its rear end to a point near its forward end where the passage connects with a` transverse passage 22 extending diametrically through the Y body. Two radial passages 2land 22 connect valve opens in response to heat from the pilotv burner for supplying gas to the pilot from the low pressure side of said safety valve. 2. In a safety control for gas heaters employing a pilot burner and a safety shut of! valve operatedthermostatically in response to heat therefrom; a manual shut oi! valve on the high pressure side of said safely shut of! valve for f supplying gas thereto,` means manually operable to supply gas to the pilot from the high pressure side of said shut of! valves for starting the pilot burner when said manual shut of! valve is closed. and means operable in response to the opening of saidmanual shut oil! valve to supply gas tothe pilot from the low pressure side of said safety,

valve'after the safety valve opens in response to h'et from the pilot burner.

- 3. A safety control for gas heaters employing a pilot burner for lighting the heater, comprising .a main shut-ol! valve having a valve body containing passages supplying gas to the heater, a thermostat responsive to heat from the flame of the pilot burner for operating said shut-oi! valve.

saidvalve body containing passages for supplying las to the pilot burner from opposite aides of the main shut-oi! valve, a two-way valve controlling said last-named passages and alternatively sup- 4. A safety control for gas' heaters a,

pilot burner lfor lighting the heater, comprising a main shut-off valve havinga valve body consaid valve body containing passages for supplymain shut-off valve for starting the burner, and

means for retaining said two-Way valve in starting position against the action of said biasing means.

shut-off valves, means normally biasing said twoway valve to supply gas to the pilot burner froml the low pressure side of the shut-oil valves,

means for manually operating said two-way valve to supply gas to the pilot burner from the high pressure side of the shut-oil valves for starting the burner. means for retaining said two-way valve in starting position against the action of said biasing means, and means on said manual shut-oir valve for releasing said retaining' means and preventing its operation when said manual shut-oi! valve is moved to open posi-` tion.

5. A safety control for gas heaters employing a pilot burner for lighting the heater, comprising a valve body having passages for supplying gas to the heater, a manual shut-off valve controlling said passages, `a. thermostatically operated shut-off valve in series with said manual shutoi valve and operable in response to heat from the ame of the pilot burner, said valve Body containing passages for supplying gas to the pilot burner from either the low pressure side of the shut-olf valve nearest the heater orthe high pressure side of the shut-off valve farthest from the heater, a two-way valve controlling said lastnamed passages and alternatively supplying gas to the pilot burner from either side of the `main 6. A safety control for gas heaters employing a pilot burner for lighting the heater, comprising a manual shut-oil valve having a valve body` containing passages for supplying gas to the heater and passages for suppl/ying gas tothe pilot burner from opposite sides of the shut-oli valve, a two-way valve controlling said last-named passages and alternatively supplyin gas to the pilot burner from either side of wlw-off valve, means normally biasing saicr'twoy valve to supply gas to the pilot burner from the low pressure side of thershut-oif valve, means for manually operating said two-Way valve to supply gas to the pilot burner from the high pressure side of the shut-off valve for starting the burner, means for retaining said two-way valve in starting position against the action of said biasing means, and means on said manual shut-o valve for releasing saidretaining means and preventing its operation when said manual shut-od 

